Data storage systems are used with a number of applications, residing on host computers connected to the data storage system, in which the virtually continuous availability of data is used for the operation of business or other entities using the applications. Generally, backup and restore operations are part of a typical information systems (IS) operation that is used to support the needs of the business. Typically, at the end of a business day or some other timeframe, any data stored on the data storage system, including any transactions, are backed up onto reels of tape or some other storage device from the host computers to another computer or server and eventually onto the tape.
With the advent of open systems and client/server technologies, information management has become increasingly complex. For example, the Symmetrix® family of data storage systems manufactured by EMC Corporation, assignee of the present invention, are capable of storing information on a plurality of different types of host systems, including but not limited to host computers or CPUs manufactured by Sun Microsystems, IBM, Hewlett-Packard, Sequent, and Siemens-Nixdorf. As the data storage systems become increasingly effective at storing data from different host computers, it is also becoming important to do both efficient and effective backups of the information contained on the data storage system. A typical application which runs on these host computers is an Oracle relational database application. Such an application is capable of managing and supporting a database which could be both very small or very large, such as hundreds of gigabytes or larger in size. Such a large database requires a high-speed efficient backup in order to prevent the lessening of the processing on the host computer or downtime of the host computer and/or applications.
The usual method of performing such a backup is to perform a backup over a network, such as a local area network (LAN) and wide area network (WAN). The EMC Data Manager (EDM™) product manufactured and sold by EMC Corporation is typical of a centralized high-performance backup system capable of handling the backup and restore needs of a user of an Oracle database (or other types of applications) over an LAN or WAN. However, although it is well known how to do a backup over a network, there are problems associated with such backups. The usual problem is that in order to backup the very large databases contained within an Oracle database, it would be desired to use a very high speed channel for performing the backups. In a network backup often the network bandwidth is not sufficient to perform a truly high-speed backup over the network. Additionally, there is usually other traffic from other servers located on the network which serve to further reduce the bandwidth of the network, causing any backup or restoration operations not to be done in a high speed manner.
The EDM product manufactured and sold by EMC Corporation has a feature termed EDM Direct Connect or Symmetrix DirectConnect which allows for the backup of data to be done without the use of a network. The backup and restoration of data is done directly between the data storage system and the server on which the backup and restore application resides. The host computer, on which the database application resides is not directly used for this backup and restore operation. This functionality is described in assignee's patent applications entitled “Logical Restore from a Physical Backup in a Computer Storage System,” “System and Method for Backing Up Data Stored in Mass Storage System Under Control of a Backup Server,” “System and Method for Backing Up Data Stored in Multiple Mirrors on a Mass Storage System Under the Control of a Backup Server,” “System and Method for Performing File-Handling Operations in a Digital Processing System Using an Operating System-Independent File Map,” and “System and Method for Generating an Operating System-Independent File Map” filed on the same day as the present patent application. This DirectConnect product takes advantage of the high-speed channels that connect a data storage system, such as the Symmetrix and the host computer and the server upon which the backup application resides. However, since the DirectConnect product is highly dependent on the internal knowledge of the individual database applications, and knowledge of how the underlying host computer system works (i.e., operating system), it is difficult and time consuming to make the DirectConnect available for use with every type of application residing on host computers with different types of operating systems. Therefore, the DirectConnect product is not currently capable of being utilized for every database or file system application, or operating system that is available on the market. Accordingly, what is needed is a database backup and restore method and system which uses the high-speed communication connection between the storage system and the host computer for certain types of communications, while using the network connection for certain types of communications. Such a hybrid use of both types of connections can be used to solve the problems associated with the use of backup and restore applications designed for the network or for direct communication with a data storage system. The present invention solves this and other problems.